is it possible to download an antivirus for nokia express music

There are Nokia Xpress music models. It is necessary to mention the model.
But as far as i know, only Nokia 5730 Xpress Music,Nokia 5630 Xpress Music and Nokia 5800 Xpress Music support anti-virus softwares. Anti-virus softwares require multi-tasking (for real-time protection) which is available only in high-end symbian phones (most of the nokia phones run on symbian ; it is necessary to know the OS it has in order to decide whether it supports multi-tasking or not). If you still have any doubts, please check your OS version. You can do this by typing "*#0000#" on your phone. you will get all the details.
Cheers.

You can download antivirus in nokia express music. But it is not working. Because you phone is s40 ,means with operating system symbian 40. And this is short version of the symbian operating system. And this operating system does not support any one of this kind of software. S60 or symbia60 can accommdate this type of softwares. It may be happen that if you download short version of any antivirus then i think you can use antivirus. If there may be exist any problem in updating in antivirus then you don't use this. Thanx........

sis file does not support in Nokia express music.Java MIDP 2.0 mobile phone does not need anti-virus, that is the good thing about your mobile phone, only symbian OS / smart phone are the mobile phones have the tendency to be infected by viruses.